Hearing the word ‘history’, we all feel somehow makes sense. We usually think history is facts about what happened in the past. However, without stopping to think, if you take one more step to try to answer the truth of ‘facts about what happened in the past’, then you will realize you can hardly define it. It tends to be a subject of controversy whether facts of the past was true or not, because it depends on the opinions of one another.
Or you could shorten “stopping to think” instead with: